From 0930cb3021b8078b34cf216e79eb8608d017864f Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Sat, 13 Oct 2018 22:03:02 +1030 Subject: _bfd_clear_contents bounds checking This PR shows a fuzzed binary triggering a segfault via a bad relocation in .debug_line. It turns out that unlike normal relocations applied to a section, the linker applies those with symbols from discarded sections via _bfd_clear_contents without checking that the relocation is within the section bounds. The same thing now happens when reading debug sections since commit a4cd947aca23, the PR23425 fix. PR 23770 PR 23425 * reloc.c (_bfd_clear_contents): Replace "location" param with "buf" and "off". Bounds check "off". Return status. * cofflink.c (_bfd_coff_generic_relocate_section): Update _bfd_clear_contents call. * elf-bfd.h (RELOC_AGAINST_DISCARDED_SECTION): Likewise. * elf32-arc.c (elf_arc_relocate_section): Likewise. * elf32-i386.c (elf_i386_relocate_section): Likewise. * elf32-metag.c (metag_final_link_relocate): Likewise. * elf32-nds32.c (nds32_elf_get_relocated_section_contents): Likewise. * elf32-ppc.c (ppc_elf_relocate_section): Likewise. * elf32-visium.c (visium_elf_relocate_section): Likewise. * elf64-ppc.c (ppc64_elf_relocate_section): Likewise. * elf64-x86-64.c *(elf_x86_64_relocate_section): Likewise. * libbfd-in.h (_bfd_clear_contents): Update prototype. * libbfd.h: Regenerate. --- bfd/libbfd.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'bfd/libbfd.h') diff --git a/bfd/libbfd.h b/bfd/libbfd.h index a8851c8..1189e63 100644 --- a/bfd/libbfd.h +++ b/bfd/libbfd.h @@ -702,8 +702,8 @@ extern bfd_reloc_status_type _bfd_relocate_contents (reloc_howto_type *, bfd *, bfd_vma, bfd_byte *) ATTRIBUTE_HIDDEN; /* Clear a given location using a given howto. */ -extern void _bfd_clear_contents - (reloc_howto_type *, bfd *, asection *, bfd_byte *) ATTRIBUTE_HIDDEN; +extern bfd_reloc_status_type _bfd_clear_contents + (reloc_howto_type *, bfd *, asection *, bfd_byte *, bfd_vma) ATTRIBUTE_HIDDEN; /* Link stabs in sections in the first pass. */ -- cgit v1.1